Introduction of YACs into mamm.cells

Hi Joris,
we introduce large YACs into murine ES cells by yeast protoplast
fusion.I have not seen anything published on the introduction
of YACs by protoplast fusion into human cells.
The limit for microinjection is currently about
600kb, and there is only one guy in this world who
made it. I cannot see any advantage of lipofection
over protoplast fusion.
Best wishes,
Andrei Popov
andrei.popov at bbsrc.ac.uk